Understanding the Changing Planet Strategic Directions for the Geographical Sciences (2010) / Chapter Skim
Currently Skimming:
1 How Are We Changing the Physical Environment of Earth's Surface?
1 How Are We Changing the Physical Environment of Earth's Surface?
Pages 21-30
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From page 21... ...
. Future climate change these biophysical changes, including habitat loss and will likely bring greater hydrological and ecological fragmentation, soil erosion, biodiversity loss, and water shifts nationally and globally, with potentially profound depletion and degradation.
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From page 22... ...
One although watershed fragmentation may be considersignificant area of investigation focuses on watershed able in the eastern United States, ecological impacts response to and recovery from environmental changes, due to flow reductions may be more significant in the including Quaternary (past 2-3 million years) climatic western part of the country.
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From page 23... ...
. and sustained changes resulting from flow regulation, These records provide the only means of identifying the including changes in channel properties, sediment processes creating climatic variability and determining transport, and reduced ecological habitat (Chin et al.
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From page 24... ...
Examples from the over long temporal scales and across space is required fluvial sciences are used to illustrate the importance of to link particular forcing factors to climatic variations. the research, largely because watershed processes are The following questions are examples of research that major landscape-forming agents.
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From page 25... ...
The application of contem- ample, have been especially affected by human activity, porary measured sediment yields to these long-term ultimately leading to demands for remediation; however, studies may lead to unknown errors in calculating the science of watershed restoration lags far behind the long-term (geological time) landscape erosion rates.
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From page 26... ...
For example, with more than of the most far-reaching future environmental changes 500 dams removed thus far in the United States and are likely to occur in regions lacking adequate data or many more targeted for removal in the relatively near long-term databases (e.g., eastern Africa, southwestern future, there is a pressing need to advance understand Asia, and the polar regions)
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From page 27... ...
. The rapid warming occurring in this vast region over the ~50 years generates major permafrost thawing, leading to significant subsurface lake drainage.
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From page 28... ...
Simi- centimeter-scale resolution of lidar offers enormous larly, remote sensing is capturing the widespread frag- opportunities in the physical sciences, especially in mentation of tropical forests (Morton et al., 2006) , documenting global sea-level change, erosion and uplift yet longer term geographical records are needed, as of mountain ranges, agricultural soil erosion, glacial are remote sensing studies and on-the-ground surveys retreat, and postflood stream-channel changes.
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From page 29... ...
, the in topography over broad areas, such as those resulting SWOT (Surface Water Ocean Topography) satellite from seismic activity along faults, ground subsidence mission offers enormous potential to monitor globaldue to groundwater or oil extraction, and changes in scale hydrological changes and map surface-water elglaciers and ice sheets (Kwok and Fahnestock, 1996; evations.
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